During the past decade there has been substantial effort expended to develop materials for the repair and replacement of various tissues, especially cartilage tissue in the knee joint. Although various polymeric biomaterials have been developed for tissue repair, these biomaterials suffer from immune incompatibility and improper distribution of stress. Furthermore, the use of material from animals, such as cow hide or cartilage from pigs or sharks, has raised concerns of possible contamination by infectious agents, such as prions. Thus, improved materials of biological origin that have improved compatibility, present a reduced risk of contamination, and provide the proper biomechanical characteristics for tissue repair are needed. In addition, these materials will preferably promote the interaction between native tissue and implanted cells. The ability to control the rate of biodegradation of these material is also desirable.